Article
Multidisciplinary Sciences
Trithep Devakul, Patrick J. Ledwith, Li-Qiao Xia, Aviram Uri, Sergio C. de la Barrera, Pablo Jarillo-Herrero, Liang Fu
Summary: We propose magic-angle helical trilayer graphene (HTG) as a platform for realizing exotic correlated topological states of matter, and provide experimental evidence and theoretical explanations.
Article
Multidisciplinary Sciences
Yiran Zhang, Robert Polski, Cyprian Lewandowski, Alex Thomson, Yang Peng, Youngjoon Choi, Hyunjin Kim, Kenji Watanabe, Takashi Taniguchi, Jason Alicea, Felix von Oppen, Gil Refael, Stevan Nadj-Perge
Summary: Graphene moire superlattices exhibit correlated insulating, topological, and superconducting phases. This study demonstrates flavor polarization and superconductivity in twisted graphene tri-, quadri-, and pentalayers on monolayer tungsten diselenide. The researchers also observed insulating states and an extended range of superconductivity as the number of layers increases.
Article
Physics, Multidisciplinary
Xiaoxue Liu, Naiyuan James Zhang, K. Watanabe, T. Taniguchi, J. I. A. Li
Summary: The discovery of magic-angle twisted trilayer graphene and its integration into a double-layer structure provides important insights into the properties and stability of the superconducting phase. The findings also contribute to the development of theoretical models aiming to understand the nature of superconductivity.
Article
Chemistry, Physical
Jeong Min Park, Yuan Cao, Li-Qiao Xia, Shuwen Sun, Kenji Watanabe, Takashi Taniguchi, Pablo Jarillo-Herrero
Summary: Superconductivity has been observed in magic-angle twisted four-layer and five-layer graphene systems, expanding the family of moire superconductors. The distinction between the twisted bilayer graphene and other members of the family is related to the movement of electrons between layers in a magnetic field. This discovery provides new insights for the design of superconducting materials platforms.
Article
Physics, Multidisciplinary
Yang-Zhi Chou, Sankar Das Sarma
Summary: In this study, we systematically investigate emergent Kondo lattice models in magic-angle twisted bilayer graphene using the topological heavy fermion representation. We demonstrate a series of symmetric strongly correlated metallic states and possibly realize a topological Dirac Kondo semimetal. The findings suggest that magic-angle twisted bilayer graphene may serve as a solid-state quantum simulator for novel magnetic orders on a triangular lattice.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Laura Classen, J. H. Pixley, Elio J. Koenig
Summary: Twistronics heterostructures provide a novel approach to control the velocity of electronic single particles and engineer strong interactions, and in turn, these interactions strongly affect the band structure. We demonstrate this mechanism with alternating-twist magic-angle three- and four-layer graphene and predict experimental consequences and behaviors at other quantum critical points.
Article
Physics, Multidisciplinary
Yuan Da Liao, Jian Kang, Clara N. Breio, Xiao Yan Xu, Han-Qing Wu, Brian M. Andersen, Rafael M. Fernandes, Zi Yang Meng
Summary: In this study, unbiased quantum Monte Carlo simulations were used to solve an effective interacting lattice model for twisted bilayer graphene (TBG) at charge neutrality. Various correlated insulating phases were discovered, including a quantum valley Hall state with topological edge states, an intervalley-coherent insulator, and a valence bond solid. These charge-neutrality correlated insulating phases provide important reference states for understanding insulating states at integer fillings and the proximate superconducting states of TBG.
Article
Physics, Multidisciplinary
Florie Mesple, Ahmed Missaoui, Tommaso Cea, Loic Huder, Francisco Guinea, Guy Trambly de Laissardiere, Claude Chapelier, Vincent T. Renard
Summary: The moire of twisted graphene bilayers can generate flat bands where charge carriers lack enough kinetic energy to escape Coulomb interactions with each other, leading to the formation of novel strongly correlated electronic states. This rich physics relies on the precise arrangement between the layers and near the magic-angle, native heterostrain dominates twist in determining the flat bands.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Haoyu Hu, B. Andrei Bernevig, Alexei M. Tsvelik
Summary: We apply a generalized Schrieffer-Wolff transformation to investigate the Kondo lattice limit of the extended Anderson-like topological heavy fermion model in magic-angle twisted bilayer graphene. We analyze the control of integer fillings and the properties of RKKY interactions and Goldstone modes in this limit.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Arup Kumar Paul, Ayan Ghosh, Souvik Chakraborty, Ujjal Roy, Ranit Dutta, K. Watanabe, T. Taniguchi, Animesh Panda, Adhip Agarwala, Subroto Mukerjee, Sumilan Banerjee, Anindya Das
Summary: Magic-angle twisted bilayer graphene exhibits unusual thermal transport phenomena, with an unusually large thermopower and peak-like features that violate the Mott formula. These behaviors arise from the particle-hole asymmetry in the electronic structure, due to the filling of the moire bands and the recovery of Dirac-like physics. The thermopower also shows an anomalous peak around the superconducting transition, suggesting the possible role of superconducting fluctuations.
Article
Multidisciplinary Sciences
Jeong Min Park, Yuan Cao, Kenji Watanabe, Takashi Taniguchi, Pablo Jarillo-Herrero
Summary: Moire superlattices have become a platform for studying correlated physics and superconductivity with unprecedented tunability. This study on magic-angle twisted trilayer graphene reveals a better tunability of electronic structure and superconducting properties than magic-angle twisted bilayer graphene, with implications for the understanding of strongly coupled superconductivity. The results suggest that the system can be electrically tuned close to the crossover to a two-dimensional Bose-Einstein condensate, indicating the potential for revolutionizing applications of superconductivity.
Article
Physics, Multidisciplinary
Pawel Potasz, Ming Xie, A. H. MacDonald
Summary: This study reports on finite-size exact-diagonalization calculations in a Hilbert space defined by the continuum-model flat moire bands of magic angle twisted bilayer graphene, showing evidence of a spin ferromagnet ground state for moire band filling between 3 and 2, and Chern insulator ground states with spontaneous spin, valley, and sublattice polarization near filling 3. It is emphasized that the inclusion of remote band self-energy is crucial for a reliable description of flat band correlations in magic angle twisted bilayer graphene.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Andrew T. Pierce, Yonglong Xie, Jeong Min Park, Eslam Khalaf, Seung Hwan Lee, Yuan Cao, Daniel E. Parker, Patrick R. Forrester, Shaowen Chen, Kenji Watanabe, Takashi Taniguchi, Ashvin Vishwanath, Pablo Jarillo-Herrero, Amir Yacoby
Summary: The discovery of unexpected incompressible states in MATBG, with Chern numbers incompatible with the simple sequential band filling assumption, can be understood as a consequence of broken translation symmetry that doubles the moire unit cell and splits each flavour band in two. These unusual incompressible phases expand the known phase diagram of MATBG and shed light on the close competition between different correlated phases in the system.
Article
Multidisciplinary Sciences
Asaf Rozen, Jeong Min Park, Uri Zondiner, Yuan Cao, Daniel Rodan-Legrain, Takashi Taniguchi, Kenji Watanabe, Yuval Oreg, Ady Stern, Erez Berg, Pablo Jarillo-Herrero, Shahal Ilani
Summary: The study reveals a transition from a low-entropy electronic liquid to a high-entropy correlated state in magic-angle twisted bilayer graphene under the influence of electron density, temperature, and magnetic field. The correlated state demonstrates a unique combination of properties associated with itinerant electrons and localized moments, with distinct energy scales for different characteristics. The hybrid nature of the correlated state and the separation of energy scales have significant implications for the thermodynamic and transport properties of twisted bilayer graphene.
Article
Materials Science, Multidisciplinary
Ammon Fischer, Zachary A. H. Goodwin, Arash A. Mostofi, Johannes Lischner, Dante M. Kennes, Lennart Klebl
Summary: Magic-angle twisted trilayer graphene is a highly tunable platform for studying correlated phases of matter. In this research, we find that spin fluctuations play an important role in superconductivity, and we discover new features in the phase diagram of the superconducting state.
NPJ QUANTUM MATERIALS
(2022)
Article
Physics, Particles & Fields
Ananda Roy, Dirk Schuricht, Johannes Hauschild, Frank Pollmann, Hubert Saleur
Summary: Analog quantum simulation using a one-dimensional quantum electronic circuit built from Josephson junctions has been investigated numerically for the quantum sine-Gordon (qSG) model. The analysis was done using density matrix renormalization group technique and compared with Bethe ansatz computations. The study shows that the quantum circuit model is less susceptible to scaling corrections compared to the XYZ chain.
Article
Multidisciplinary Sciences
Yonglong Xie, Andrew T. Pierce, Jeong Min Park, Daniel E. Parker, Eslam Khalaf, Patrick Ledwith, Yuan Cao, Seung Hwan Lee, Shaowen Chen, Patrick R. Forrester, Kenji Watanabe, Takashi Taniguchi, Ashvin Vishwanath, Pablo Jarillo-Herrero, Amir Yacoby
Summary: Fractional Chern insulators (FCIs) are lattice analogues of fractional quantum Hall states and have been recently observed in magic-angle twisted BLG at low magnetic field. The appearance of these states at 5 T is accompanied by the disappearance of nearby topologically trivial charge density wave states.
Article
Physics, Multidisciplinary
Andrew T. Pierce, Yonglong Xie, Jeong Min Park, Eslam Khalaf, Seung Hwan Lee, Yuan Cao, Daniel E. Parker, Patrick R. Forrester, Shaowen Chen, Kenji Watanabe, Takashi Taniguchi, Ashvin Vishwanath, Pablo Jarillo-Herrero, Amir Yacoby
Summary: The discovery of unexpected incompressible states in MATBG, with Chern numbers incompatible with the simple sequential band filling assumption, can be understood as a consequence of broken translation symmetry that doubles the moire unit cell and splits each flavour band in two. These unusual incompressible phases expand the known phase diagram of MATBG and shed light on the close competition between different correlated phases in the system.
Article
Multidisciplinary Sciences
Joe Finney, Aaron L. Sharpe, Eli J. Fox, Connie L. Hsueh, Daniel E. Parker, Matthew Yankowitz, Shaowen Chen, Kenji Watanabe, Takashi Taniguchi, Cory R. Dean, Ashvin Vishwanath, M. A. Kastner, David Goldhaber-Gordon
Summary: We present transport measurements of bilayer graphene with a 1.38 degrees interlayer twist. Although we do not observe correlated insulating states or band reorganization, we do observe several highly unusual behaviors in magnetotransport, including large and quadratic magnetoresistance for a large range of densities around half filling of the moire bands, as well as the splitting and bending of magnetoresistance minima corresponding to gaps between Landau levels as a function of density and field. These features appear to be a generic class of experimental manifestations of Hofstadter's butterfly and may provide insight into the emergent states of twisted bilayer graphene.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Quantum Science & Technology
Sajant Anand, Johannes Hauschild, Yuxuan Zhang, Andrew C. Potter, Michael P. Zaletel
Summary: Traditional approaches to quantum simulation are limited by the number of qubits needed, but holographic quantum simulation allows for the simulation of larger systems using a subset of qubits. We utilized the multiscale entanglement renormalization ansatz (MERA) and the Quantinuum trapped-ion computer to accurately prepare the ground state and measure correlations of a perturbed Ising model. Generalized MERA networks were introduced to capture longer correlations than traditional MERA networks.
Article
Materials Science, Multidisciplinary
Jakob Unfried, Johannes Hauschild, Frank Pollmann
Summary: We propose a modified time-evolving block decimation algorithm that uses QR decomposition for truncation instead of SVD. The modification reduces the scaling with the dimension of the physical Hilbert space and allows for efficient GPU implementations. Benchmark simulation shows a significant speedup using QR updates compared to SVD updates on an A100 GPU.
Article
Physics, Multidisciplinary
Shannon C. Haley, Sophie F. Weber, Taylor Cookmeyer, Daniel E. Parker, Eran Maniv, Nikola Maksimovic, Caolan John, Spencer Doyle, Ariel Maniv, Sanath K. Ramakrishna, Arneil P. Reyes, John Singleton, Joel E. Moore, Jeffrey B. Neaton, James G. Analytis
PHYSICAL REVIEW RESEARCH
(2020)
Article
Materials Science, Multidisciplinary
Tomohiro Soejima, Daniel E. Parker, Nick Bultinck, Johannes Hauschild, Michael P. Zaletel
Article
Materials Science, Multidisciplinary
Daniel E. Parker, Xiangyu Cao, Michael P. Zaletel
Article
Materials Science, Multidisciplinary
Ananda Roy, Johannes Hauschild, Frank Pollmann
Article
Materials Science, Multidisciplinary
Johannes Hauschild, Eyal Leviatan, Jens H. Bardarson, Ehud Altman, Michael P. Zaletel, Frank Pollmann
Article
Materials Science, Multidisciplinary
Daniel E. Parker, Thomas Scaffidi, Romain Vasseur
